jerk (v.1)

"to pull with sudden energy," 1580s; earlier "to lash, strike as with a whip" (1540s, surviving only in dialect), of uncertain origin, perhaps echoic. Intransitive sense of "make a sudden spasmodic motion" is from c. 1600. Compare Middle English yerkid, an adjective apparently meaning "pulled tight" (early 15c.), which has the form of a past participle. Also compare Middle English ferken "move hastily; drive (something) forward," from Old English fercian "to proceed." Related: Jerked; jerking.

A soda-jerk (1915; soda-jerker is from 1883) is so called for the pulling motion required to work the taps.

The SODA-FOUNTAIN CLERK

Consider now the meek and humble soda-fountain clerk,

Who draweth off the moistened air with nimble turn and jerk,

[etc., "Bulletin of Pharmacy," Detroit, Michigan, August, 1902]

jerk (n.1)

1550s, "stroke of a whip," from jerk (v.1). Sense of "sudden sharp pull or twist" first recorded 1570s. Meaning "involuntary spasmodic movement of limbs or features" first recorded 1805. As the name of a popular dance, it is attested from 1966.

jerk (v.2)

"preserve (meat) by cutting into long thin strips and drying in the sun," 1707, American English, from American Spanish carquear, from charqui (see jerky). Related: Jerked.